Hmm, I just read the walkthrough on GameFAQs, and I don't really like it.
The author said it was impossible to kill the dog in the old mine, and even I managed to do this, in hard difficulty, though I'm really bad at action games.
And the walkthrough gives too much away in my opinion.
I know telling players what to do is the idea behind walkthrughs, but in the gamefaq text, every single step is decribed in a painfully detailed way, with no single thought left to think for the player. Walkthroughs like that kill the mood of a game
That doesn't mean I don't appreciate the work put into it, I just don't like the result.
The one pikacz wrote is how a walkthrough should be, I think.
There are directions in it on what to do, and what you can find in a room, but the player still has to figure some stuff out, without being guided like a blind robot. This way most of Penumbra's atmosphere is preserved.